Shock wave

In physics, a shock wave or shock is a type of propagating disturbance. When a wave moves faster than the local speed of sound in a fluid it is a shock wave. Like an ordinary wave, a shock wave carries energy, and can propagate through a medium; however it is characterized by an abrupt, nearly discontinuous change in pressure, temperature and density of the medium. In supersonic flows, expansion is achieved through an expansion fan also known as a Prandtl-Meyer expansion fan.

Unlike solitons (another kind of nonlinear wave), the energy of a shock wave dissipates relatively quickly with distance. Also, the accompanying expansion wave approaches and eventually merges with the shock wave, partially cancelling it out. Thus the sonic boom associated with the passage of a supersonic aircraft is the sound wave resulting from the degradation and merging of the shock wave and the expansion wave produced by the aircraft.

When a shock wave passes through matter, energy is preserved but entropy increases. This change in the matter's properties manifests itself as a decrease in the energy which can be extracted as work, and as a drag force on supersonic objects; shock waves are strongly irreversible processes.

Shockwaves (Unkle Bob album)

Track listing

Red Hot Rhythm & Blues

Red Hot Rhythm and Blues is a 1987 studio album by the American singer Diana Ross released via EMI and RCA labels.

Overview

The album made the charts in the UK, Germany, the Netherlands and Austria, as well as reaching the top 20 in Sweden and Norway. It was Ross's final album for RCA Records. It peaked at No. 73 on the "Billboard album chart in the US despite an Emmy nominated television special that was a ratings success. It sold around 125,000 copies in the USA.

The album included the Top 15 US R&B and UK Top 50 hit, "Dirty Looks", written by Richard Scher & Lotti Golden, and the ballad "It's Hard for Me to Say", produced by Luther Vandross. It also included cover versions of several R&B classics, including The Bobbettes' "Mr. Lee", Jackie Ross' "Selfish One," Etta James' "Tell Mama", and The Drifters' "There Goes My Baby". A Shep Pettibone remix of "Shockwaves" was released as a single in the UK which peaked at #76.

The album was promoted with a TV special featuring Etta James, Little Richard, Billy Dee Williams, Leslie Nielsen, LL Cool J, Bernadette Peters and Wolfman Jack. The tracks "Mr Lee" and "Tell Mama" did not feature on the US version of the album and the mix of "Dirty Looks" was the UK version which differs from the US version.